JPH08130127A - High voltage transformer and discharge lamp circuit - Google Patents

Abstract

PURPOSE: To make the mounting to a substrate easier and to improve vibration resistance by reducing the size and weight. CONSTITUTION: A core 19 is housed in a spool 18 and a secondary winding 17a is wound. These are housed in a case 80 and covered with a filling resin, and fixed and formed in one united body. A conductive holder 82 is inserted and formed in the case 80 thereby functioning as a primary winding. A high voltage end of the secondary winding 17 is taken out through a high voltage cord 83. On the other hand, a low voltage end of the secondary winding 17a is connected to a wiring pattern of a substrate 21. The conductive holder 82 has a cover portion 82c through which the primary current does not flow, and this cover portion 82c covers the high voltage end side of the secondary winding 17a and functions as a shield plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high voltage transformer and a discharge lamp circuit.

[0002]

2. Description of the Related Art A high voltage is required to start a high-pressure discharge lamp (for example, a metal halide lamp). Especially, when the high-pressure discharge lamp is used as a vehicle headlight, it is restarted immediately after being turned off. In particular, a high starting voltage is required in order to ensure the reliability. Therefore, in the discharge lamp circuit, a high voltage transformer as shown in FIG. 15 is generally used. The conventional high-voltage transformer includes a secondary spool 210 having a substantially hollow cylindrical shape around which the secondary winding 200 is wound, a core 220 having a substantially cylindrical shape inserted into a hollow portion of the secondary spool 210, A primary side spool 240 around which a primary winding 230 is wound so as to surround the secondary winding 200 is housed in a resin case 250 and filled with an insulating material 260 such as an epoxy resin. .

However, the conventional high-voltage transformer as described above is large in size and heavy in weight, so that it is difficult to mount it on a printed board from the viewpoint of difficulty in miniaturization and difficulty in ensuring vibration resistance. . Moreover, since the high-voltage transformer generates a high voltage enough to start the high-pressure discharge lamp, it may affect other electric components on the printed circuit board and damage them. For this reason, for example, it was necessary to take measures such as installing semiconductor element parts away from the high-voltage transformer or installing a shield member between the semiconductor element parts and the high-voltage transformer. There is a problem in that the number of circuits increases and the size of the entire circuit, and thus the circuit container, increases.

On the other hand, a current transformer disclosed in Japanese Utility Model Laid-Open No. 61-7020 is known as a transformer mounted on a printed circuit board. In this technique, the detection winding, which is the primary winding, is made of a plate or wire material that is bent in a U shape in advance. Then, the detection winding is directly inserted into and fixed to the printed circuit board. However, this current transformer has a problem that the core is exposed and it is not suitable for high voltage applications. In addition, since the secondary winding is only insulated with an insulating tape, there is a problem that it is not suitable for high voltage applications in terms of pressure resistance and influence on surrounding electric parts.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved high voltage transformer and discharge lamp circuit in view of the problems of the prior art described above. It is an object of the present invention to reduce the size and weight of a high-voltage transformer and a discharge lamp circuit, and to easily mount the high-voltage transformer on a circuit board on which electric parts are mounted.

Another object of the present invention is to provide a high voltage transformer and a discharge lamp circuit which prevent other electric parts from being adversely affected by the high voltage generated by the high voltage transformer.

[0007]

In order to achieve the above object, the present invention provides a high voltage transformer including a core, a secondary winding, and a primary winding, which covers the core and the secondary winding. A high-voltage transformer comprising: an insulating material to be integrated; and a conductive holder, which is arranged so as to surround the secondary winding as the primary winding and has fixing portions for fixing to a base at both ends. Adopt technical means.

The conductive holder may be integrally formed in the insulating material. Further, the insulating material includes a resin case and a filling resin filled in the case, the core and the secondary winding are housed in the case, and the filling resin is filled in the insulating material. You may employ | adopt the structure integrated in the case. In this case, the case may be provided with a connecting portion with the base.

The conductive holder may cover at least the high voltage end of the secondary winding. In this case, it is preferable that the conductive holder is configured to have a main energization part through which a current as the primary winding flows, and a cover part that extends from the main energization part and covers the high-voltage end. It also has a high voltage cord,
A configuration may be adopted in which the high voltage end of the secondary winding is connected to the high voltage cord.

In order to achieve the above object, the present invention provides a high voltage transformer having a core, a secondary winding, and a primary winding.
In a discharge lamp circuit mounted on a board on which other electric components are mounted, the high-voltage transformer includes an insulating material that covers and integrates the core and the secondary winding, and the secondary winding as the primary winding. A conductive holder, which is arranged so as to surround and is provided with fixing portions to the substrate at both ends, is connected to the conductive pattern of the substrate and both ends of the conductive holder in an electrically conductive state. Adopt the technical means of.

A configuration may be adopted in which at least the low voltage end of the secondary winding is connected to the conductive pattern of the substrate. Also, the discharge lamp circuit is housed in a circuit container, and the conductive holder has a cover portion that extends between other electrical components in the circuit container and the high-voltage end of the secondary winding. The configuration may be adopted.
In this case, it is preferable that the conductive holder has a main conducting portion through which a current as the primary winding flows, and the cover portion is formed to extend from the main conducting portion.

Further, a structure may be adopted in which a high voltage cord separate from the conductive pattern of the substrate is provided and the high voltage end of the secondary winding is connected to the high voltage cord.

[0013]

According to the high-voltage transformer of the present invention, the conductive holder exerts both the function as the primary winding and the function as the fixture for fixing the secondary winding to the base. In addition, the number of parts and the number of assembling steps can be reduced. Moreover, since the core of the high-voltage transformer and the secondary winding are both covered with the insulating material and integrated, it is possible to prevent the high-voltage output from directly leaking even if a high-voltage output is generated. While simplifying the configuration,
The performance required for the high voltage transformer can be realized.

When the conductive holder is integrally molded in the insulating material, the generation of the capacitive component can be made constant. Further, when the structure in which the core and the secondary winding are housed in the case and filled with an insulating material to be integrated in the case is adopted, the core and the secondary winding are easily and surely integrated. be able to. In this case, it is possible to simplify positioning and fixing to the base by forming a connecting portion with the base on the case.

When the conductive holder covers at least the high voltage end of the secondary winding, the high voltage output can be shielded from the outside with a simple structure.
In this case, by configuring the conductive holder to have a main conducting portion through which a current as the primary winding flows and a cover portion that extends from the main conducting portion and covers the high voltage end, the current contributing to electromagnetic coupling is obtained. It is possible to shield the high voltage output from the outside while concentrating the power on the main energizing section to achieve high efficiency.

Further, by adopting the structure in which the high voltage end of the secondary winding is connected to the high voltage cord, the high voltage output can be taken out safely. According to the discharge lamp circuit of the present invention, it is possible to reduce the size and weight of the high-voltage transformer and to supply the primary current directly to the conductive holder of the high-voltage transformer from the conductive pattern of the substrate. Moreover, the high voltage transformer can be mounted and fixed by the conductive holder at the same time as the electrical connection for energizing the primary current.

By adopting a structure in which at least the low-voltage end of the secondary winding is connected to the conductive pattern of the substrate, it is possible to easily form an energization path for the secondary current, and yet to reduce the low-voltage of the secondary winding. Since no high voltage appears at the edges, it does not affect other electrical components on the board. In addition, the discharge lamp circuit is accommodated in the circuit container, and the conductive holder has a cover portion that spreads between the other electrical components in the circuit container and the high-voltage end of the secondary winding. High voltage can be shielded against other electrical components within the container.

In this case, the conductive holder is configured to have a main conducting portion through which a current as the primary winding flows, and a cover portion extending from the main conducting portion and covering the high voltage end, so that electromagnetic coupling is achieved. It is possible to shield the high voltage output from other electric components in the circuit container while concentrating the contributing current in the main energizing portion to achieve high efficiency. In addition, by adopting a configuration in which the high-voltage end of the secondary winding is connected to a high-voltage cord that is separate from the conductive pattern of the board, other electrical components mounted on the board or other electrical components in the circuit container are The high voltage can be taken out while suppressing the influence of the high voltage on the parts.

[0019]

Embodiments of the high voltage transformer to which the present invention is applied and a discharge lamp circuit using the high voltage transformer will be described below. First Embodiment FIG. 1 shows the circuit configuration of a discharge lamp circuit according to the first embodiment.

In FIG. 1, reference numeral 1 denotes a vehicle battery, 2
Represents a headlight switch. Reference numeral 3 denotes a DC / DC converter, and the DC / DC converter 3 is configured so that its output can be changed according to the output of the power control circuit 4. Reference numerals 5 and 6 denote voltage detection resistors, 7 denotes a high pressure discharge lamp composed of a metal halide lamp, and 8 denotes a current detection resistor for detecting a current flowing through the high pressure discharge lamp 7. Reference numeral 9 represents a capacitor for short-circuiting the low-voltage side terminal of the secondary winding of the high-voltage transformer 17 and the high-pressure discharge lamp 7 in an AC manner. Reference numeral 10 represents a starting circuit. The starting circuit 10 includes a starting control circuit 11, a transistor 12, a step-up transformer 13, a rectifying diode 14, and a capacitor 1.
5, a discharge tube 16 and a high voltage transformer 17.

In this embodiment, all the circuits except the high pressure discharge lamp 7 are housed in one circuit container 100. In particular, the high voltage transformer 17 of the starting circuit 10 and other electric components of the starting circuit 10 are mounted on a common printed wiring board. Next, the operation of the discharge lamp circuit having the above configuration will be described. When the headlight switch 2 is turned on, the start control circuit 11 generates a high frequency output, whereby the transistor 12 is turned on and off and a boosted high frequency voltage is generated on the secondary side of the step-up transformer 13. This high frequency voltage is rectified by the rectifying diode 14, and the charging voltage of the capacitor 15 gradually rises. Then, when the charging voltage rises to the discharging voltage determined by the gap of the discharge tube 16, the discharging tube 16 is discharged, and the charge charged in the capacitor 15 is instantaneously discharged. By this discharge, the high voltage transformer 1
A high voltage of 20 to 30 kV is generated on the secondary side of 7.
Such an operation is repeated and the high-pressure discharge lamp 7 starts to discharge and reaches lighting. When the high pressure discharge lamp 7 is turned on, the start control circuit 11 keeps the transistor 12 in the off state thereafter. Therefore, after the high-pressure discharge lamp 7 is turned on, electric power is supplied to the high-pressure discharge lamp 7 from the DC / DC converter 3, and the secondary winding 17 a of the high-voltage transformer 17 is constantly supplied with the discharge current of the high-pressure discharge lamp 7. It comes to flow. The power supplied to the DC / DC converter 3 is detected based on the voltage detected by the voltage detection resistors 5 and 6 and the current detected by the current detection resistor 8, and the power control circuit 4 is based on this detected power. DC /
The DC converter 3 is controlled.

Next, details of the high voltage transformer 17 will be described with reference to FIGS. 2 is an exploded perspective view of the high-voltage transformer according to the first embodiment, and FIG. 3 is a sectional view of the high-voltage transformer 17. In FIG. 2, the secondary winding 17a is wound around a hollow cylindrical spool 18. Spool 18
Is housed in a resin case 20 having a substantially U-shaped cross section with a cylindrical core (for example, a ferrite core) 19 inserted in the hollow portion, and an epoxy resin 20b as a filling resin is placed in the case 20. It is filled and integrated with the case 20. Both ends of the secondary winding 17a are passed through a pair of round holes 21a, 21a provided in the substrate 21,
1 is electrically connected to the high-pressure discharge lamp 7, the current detection resistor 8 and the capacitor 9 shown in FIG. 1 via wiring patterns 24, 24 as conductive patterns formed on the back surface 21c of the.

The conductive holder 2 is provided on the outer peripheral surface of the case 20.
A recess 20a into which 2 is fitted is formed. The conductive holder 22 is made of a plate-shaped copper plate, has a substantially inverted U-shaped cross section,
The secondary winding 17a is surrounded within one turn or less. At both ends of the conductive holder 22, the claw portions 22a, 22 are press-fitted into the pair of square holes 21b, 21b provided in the substrate 21.
a is formed. The conductive holder 22 is the case 20.
The claw portions 22a, 22a are fixed to the substrate 21 by being fitted into the concave portions 20a, press-fitted into the pair of square holes 21b, 21b, and bent. The claw portions 22a, 22a come into contact with the wiring patterns 23, 23 of the board 21 and are further soldered. The claw portions 22a, 22a are electrically connected to the discharge tube 16 and the DC / DC converter 3 shown in FIG. 1 via the wiring patterns 23, 23. In this way, the conductive holder 22 is configured as a primary winding.

In the high voltage transformer configured as described above, the conductive holder 22 has a function as a primary winding and a fixing for fixing an integrated unit including the secondary winding 17a to the substrate 21. Demonstrate both functions as a tool. Therefore, the primary side spool can be omitted and the filling amount of the filling resin can be reduced. Therefore, the high-voltage transformer can be reduced in size and weight, can be easily mounted on the substrate 21, and can be improved in vibration resistance.

Further, since the conductive holder 22 is a plate-shaped member, the secondary winding 17a can be firmly attached to the substrate 21 and the vibration resistance is improved. In addition, the secondary winding 17
The magnetic flux distribution interlinking with a can be made uniform. Second Embodiment This second embodiment is a modification of the first embodiment and includes a substrate 21.
The shape of the wiring patterns 23, 23 on the back surface and the bending direction of the claw portions 22a, 22a of the conductive holder 22 are changed. These changes will be described.

FIG. 4 shows the back surface of the substrate 21 of the second embodiment. The wiring patterns 23, 23 formed on the rear surface 21c of the substrate 21 are the high voltage transformer 1 mounted on the front surface of the substrate.
The lower surface of 7 has portions 23a, 23a extending in a direction orthogonal to the core 19. With this portion, the wiring pattern can be made to have a function as a part of the primary winding, and the magnetic flux generated in the primary winding can be increased.

If it is desired to further increase the number of interlinkage magnetic fluxes, two conductive holders 22 may be used and connected in series by using a wiring pattern. Third Embodiment This third embodiment is a modification of the first embodiment and includes a substrate 2
(1) The shape of the wiring pattern on the back surface, the shape of the holes into which the conductive holders are inserted, and the shape and number of the conductive holders are changed. These changes will be described.

FIG. 5 is an exploded perspective view of the high voltage transformer of the third embodiment. In FIG. 5, a linear recess 20 into which two linear conductive holders are fitted is provided on the outer peripheral surface of the case 20.
a and 20a are formed. Each conductive holder 32, 3
Reference numeral 2 denotes two linear U-shaped linear copper wires. Both ends of the conductive holders 32, 32 are inserted into the pair of round holes 21d, 21d, 21d, 21d of the board 21 and soldered to the wiring patterns 23, 2 of the board 21.
It is fixed in a state of being electrically connected to 3, 25. Here, since the wiring pattern 25 electrically connects the two conductive holders 32, 32 as is clear from the figure, the two conductive holders 32, 32 and the wiring pattern 25 are connected to each other. A primary winding having a number of turns of "2" is configured.

In the high voltage transformer constructed as described above, the same effect as that of the first embodiment can be obtained. Moreover, the number of turns of the primary winding can be set to "2" with a simple configuration, and the magnetic flux can be increased. Further, since the conductive holders 32, 32 are linear bodies, the conductive holder can be easily processed.

Further, since the conductive holders 32, 32 are composed of a plurality, the secondary winding 17a can be firmly attached to the substrate 21 and the vibration resistance is improved. Fourth Embodiment This fourth embodiment is a modification of the first embodiment and includes a substrate 2
The method of fixing the conductive holder with respect to No. 1 is changed. This change will be described.

FIG. 6 is an exploded perspective view of the high voltage transformer of the fourth embodiment. In FIG. 6, a recess 20a into which the plate-shaped conductive holder 42 is elastically fitted is formed on the outer peripheral surface of the case 20. Fixed portions 42a, 42a are formed at both ends of the conductive holder 42.
a and 42a are fixed to the surface of the substrate 21 with a fixing tool (not shown) such as a screw, so that the conductive holder 42
Is fixed to the substrate 21 while holding the case 20. A fixing tool such as a screw tightens the lead wire together with the conductive holder 42 to electrically connect the conductive holder 42 and the lead wire. Then, it is electrically connected to the discharge tube 16 and the DC / DC converter 3 shown in FIG. 1 through this lead wire.

In the high voltage transformer configured as described above, the same effect as that of the first embodiment can be obtained. Further, since the conductive holder 22 is a plate-shaped member and is attached to the substrate 21 using a fixture such as a screw, the secondary winding 17a can be firmly attached to the substrate 21,
Vibration resistance is improved.

Fifth Embodiment In the plurality of embodiments described above, only the conductive holder is separately provided for the unit integrated with the case and the filling resin. The holder is insert-molded beforehand in the case. In the configuration of the first embodiment, the secondary winding 17a that generates a high voltage
The stray capacitance between the conductive holder 22 and the conductive holder 22 can be understood as an equivalent circuit model shown in FIG. In FIG. 7, V _17a is a voltage generated in the secondary winding, C ₁ is a stray capacitance composed of an insulating material filled in the case 20, and C ₂ is a wall thickness of the case 20. The stray capacitance, C _3, is a stray capacitance formed by the space between the case 20 and the conductive holder 22. Here, when the high voltage transformer 17 is operated in the air, since the relative magnetic permeability of the air is small, the stray capacitances C ₁ and C _{2 are}
The capacity of C ₃ is relatively smaller than that of. Therefore, Case 2
A relatively large voltage is applied between 0 and the conductive holder 22, and partial dielectric breakdown is likely to occur.

In order to prevent such dielectric breakdown,
By filling the entire high-voltage transformer 17 with another insulating material such as silicon rubber without any gap, the value of the stray capacitance C ₃ formed between the case 20 and the conductive holder 22 is increased, and the high voltage is applied to the corresponding portion. A possible method is to prevent the addition of. However, this method is not a good idea considering the increase in weight and cost associated with filling.

FIG. 8 is an exploded perspective view of the high voltage transformer 17 of the fifth embodiment. The fifth embodiment is a modification of the high voltage transformer case and the conductive holder of the first embodiment. These changes will be described. In FIG. 8, the conductive holder 52 is embedded in the resin forming the case 50 and is integrally insert-molded.

According to the high voltage transformer 17 of the fourth embodiment, the same effect as that of the first embodiment can be expected. Further, since the case 50 and the conductive holder 52 are in close contact with each other, there is no possibility of causing dielectric breakdown between them. Moreover, such insulation breakdown can be prevented with a simple configuration. Furthermore, since both the case 50 and the conductive holder 52 are integrally molded, the fixing to the substrate 21 is ensured. Sixth Embodiment Sixth Embodiment FIG. 9 is an exploded perspective view of the high voltage transformer 17 of the sixth embodiment. The sixth embodiment is a modification of the case and the conductive holder of the high voltage transformer of the third embodiment shown in FIG. These changes will be described.

The two linear conductive holders 62, 62 are
It is a metal conductor corresponding to the next winding, and is preliminarily embedded and molded in a resin case 60 with both ends 62a exposed. Since the high voltage transformer 17 according to the sixth embodiment is configured as described above, in addition to the effect obtained in the third embodiment, the same effect as in the fifth embodiment is obtained. Seventh Embodiment FIG. 10 is an exploded perspective view of a high voltage transformer 17 of a seventh embodiment. The seventh embodiment is a modification of the case and the conductive holder of the high voltage transformer of the fourth embodiment shown in FIG. These changes will be described.

The conductive holder 72 is a metal conductor corresponding to the primary winding, and is pre-embedded in the resin case 70 with both ends 72a exposed. Since the high voltage transformer 17 according to the seventh embodiment is configured as described above, in addition to the effect obtained in the fourth embodiment, the same effect as the fifth embodiment can be obtained. Eighth Embodiment This eighth embodiment is a modification of the high voltage transformer and discharge lamp circuit of the fifth embodiment. In the eighth embodiment, the shapes of the case of the high-voltage transformer, the conductive holder and the secondary winding, and the arrangement of the board on which the discharge lamp circuit is mounted are changed. These changes will be described.

FIG. 11 is an exploded perspective view of a high voltage transformer and a discharge lamp circuit of the eighth embodiment, and FIG. 12 is a developed view of a conductive holder. The resin case 80 is formed in a U-shaped cross section having walls at both ends. Positioning protrusions 80a for the substrate 21 are integrally formed at the four corners of the opening end. Further, a slit 80b is formed on one end side of the case 80, particularly on the end wall on the high pressure side.

In the case 80, a conductive holder 82 is insert-molded with both ends 82a thereof exposed. The conductive holder 82 has both ends 82a, 82a.
It has a main current-carrying portion 82b connecting between them, and a cover portion 82c extending from a substantially central portion of the main current-carrying portion 82b and extending over the same circumferential range as the main current-carrying portion 82b. As shown in FIG. 11, the cover portion 82c extends so as to cover only the high voltage output side of the secondary winding 17a. Such a conductive holder 82 is obtained by pressing a plate material and forming the slits 82d and 82d while leaving the connecting portion 82e.

A core 19 is accommodated in the spool 18,
The secondary winding 1 is continuously provided in the three slots of the spool 18.
7a is wound. The low voltage end of the secondary winding 17a is connected to the lead wire 18a fixed to the spool 18. On the other hand, the high voltage end of the secondary winding 17a is connected to the high voltage cord 83 supported by the end flange of the spool 18. These parts are housed in a case 80 and
It is embedded and fixed by a filling resin as in the embodiment.
At this time, the high-voltage cord 83 is led out from the slit 80b of the case 80, and the slit 80b is further attached to the spacer 80c.
Close with. As a result, the high voltage end of the secondary winding 17a can be directly taken out without passing through the substrate 21. The high voltage cord 83 is taken out through the wall surface of the circuit container 100 and connected to the discharge lamp 7.

In addition to the holes 21a into which the leads 18a are inserted and soldered on the back surface and the holes 21b and 21b into which the end portions 82a are inserted and soldered on the back surface, a positioning protrusion 80a is inserted into the substrate 21. Holes 21c, 21
c, 21c, 21c are formed. In addition, the density of the electric components in the circuit container 100 is increased, and the circuit container 10
In order to reduce the size of the board 0, a board 84 provided vertically to the board 21 is housed in the circuit container. The electric components 85 other than the high-voltage transformer 87 are mounted on the board 21 as well.
An electric component 86 such as an IC circuit is also mounted on the substrate 84.

When the high voltage transformer 87 is mounted on the substrate 21, a part of the electric component 86 is located near the high voltage end side. When the high-voltage transformer 87 operates, a high voltage of several tens of kv is generated, and an abnormal voltage may be induced in the peripheral conductive material. However, in this embodiment, the cover portion 82c substantially covers the high-voltage end side, and since the cover portion 82c is connected to the low-voltage primary side through the connecting portion 82e, it functions as a shield plate. High voltage transformer 87
It prevents the electrical parts installed near the car from being adversely affected. By adopting such a configuration, the high-voltage transformer 87 that generates a high voltage and the electric component 86 that operates at a low voltage and has a low withstand voltage can be housed in the circuit container 100 at a high density. Moreover, a high-voltage shield can be realized at a low cost with a simple structure using a part of the conductive holder 82. Moreover, the cover portion 82c as the shield plate is
Only the connecting portion 82e is connected to the main energizing portion 82b,
No primary current flows. Therefore, the primary current is supplied to the main energizing portion 82.
Therefore, a large amount of magnetic flux interlinking with the secondary winding 17a can be secured.

Ninth Embodiment This ninth embodiment is a modification of the high voltage transformer of the eighth embodiment. In this ninth embodiment, the case of the high voltage transformer,
The shapes of the conductive holder and the secondary winding are changed. These changes will be described. FIG. 13 is an exploded perspective view of a high voltage transformer 97 of the ninth embodiment, and FIG. 14 is a development view of a conductive holder of the ninth embodiment.

The case 90 made of resin is formed to be narrower than the case 80 of the eighth embodiment, and has a positioning protrusion 90a and a slit 90b like the case 80. In the case 90, a conductive holder 92 is insert-molded with both ends 92a thereof exposed. The conductive holder 92 is divided by the slit 92e, and both ends 92a, 9a are separated.
Two main energization parts 92b, 92c located in parallel between 2a
And a cover portion 92d which extends from substantially the central portion of the main conducting portion 92c and spreads over substantially the same circumferential range as the main conducting portion 92c. The cover portion 92d is shown in FIG.
As shown in FIG. 3, it extends so as to cover only the high voltage output side of the secondary winding 96. Such a conductive holder 9
2 is a plate material that is pressed, leaving the connecting portion 92h.
f, 92 g are obtained. The conductive holder is formed wider than the conductive holder 82 of the eighth embodiment in accordance with the slimming of the secondary winding 96.

A core 99 is accommodated in the spool 98. There is no slot on the outer circumference of the spool 98, and only one layer of the secondary winding 96 is wound on the outer circumference of the spool 98 from one end to the other end. The low voltage end of the secondary winding 93 is connected to a lead wire 98 a fixed to the spool 98. On the other hand, the high-voltage end of the secondary winding 96 is connected to the high-voltage cord 93 supported by the end flange of the spool 98. These parts are housed in the case 90, and are embedded and fixed by the filling resin as in the first embodiment. At this time, the high-voltage cord 93 is led out from the slit 90b of the case 90, and the slit 90b is closed by the spacer 90c. In addition, as compared with the eighth embodiment,
The high voltage transformer of the ninth embodiment has an elongated structure along the axial direction of the core. Thereby, the height dimension can be suppressed.

The board on which the high-voltage transformer 97 is mounted is provided with holes and wiring patterns that match the high-voltage transformer 97. According to the ninth embodiment, it is possible to further reduce the size of the high voltage transformer. Modifications In the above-described embodiments, the printed wiring board is used as an example of the base, but the high-voltage transformer may be attached using the circuit case or the dedicated bracket as the base. In this case, an electric wire such as a lead wire (not shown) is used as the wiring for energization, and this electric wire is used in the fourth and seventh embodiments.
It is electrically connected to both ends of the conductive holder by the screws or the like used in the embodiments.

Further, in the structure for integrating the core and the secondary winding, it is important that these are covered and integrated with an insulating material. Therefore, without using a case, the core and the secondary winding may be mounted as an insert body in the molding cavity, and resin molding may be performed so as to include them. Alternatively, the core, the secondary winding, and the conductive holder may be housed in the case and integrated with the filling resin. Further cost reduction is possible.

Further, both or one of the claw portions 22a, 22a of the conductive holder 22 having the shape shown in the first embodiment may be extended, and this extended portion may be bent so as to surround the secondary winding.
With such a configuration as well, the primary windings that substantially surround the entire circumference of the secondary winding 17a can be formed on both the front and back sides of the substrate 21.
The conductive holder described in the third embodiment may be only one. In this case, one conductive holder is attached to the substrate 2
The outer peripheral surface of the case 20 is wound twice, such that it is passed through the back surface 21c of 1 and then through the front surface.
At this time, two slits extending from the outer peripheral edge of the substrate 21 may be formed, and the conductive holder may be wound around the slit together with the case 20.

As the winding method of the secondary winding, various windings such as oblique overlap winding can be adopted in addition to the structure of winding the spool with a slot. Further, the positioning protrusion formed on the case may be melted on the back surface of the substrate, and the case may be directly fixed to the substrate.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a discharge lamp circuit according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the high voltage transformer according to the first embodiment.

FIG. 3 is a sectional view of the high voltage transformer according to the first embodiment.

FIG. 4 is a plan view of a substrate according to a second embodiment.

FIG. 5 is an exploded perspective view of a high voltage transformer according to a third embodiment.

FIG. 6 is an exploded perspective view of a high voltage transformer according to a fourth embodiment.

FIG. 7 is an equivalent circuit diagram considering the stray capacitance of the high voltage transformer.

FIG. 8 is an exploded perspective view of a high voltage transformer according to a fifth embodiment.

FIG. 9 is an exploded perspective view of a high voltage transformer according to a sixth embodiment.

FIG. 10 is an exploded perspective view of a high voltage transformer according to a seventh embodiment.

FIG. 11 is an exploded perspective view of a high voltage transformer and a discharge lamp circuit according to an eighth embodiment.

FIG. 12 is a development view of a conductive holder according to an eighth embodiment.

FIG. 13 is an exploded perspective view of a high voltage transformer according to a ninth embodiment.

FIG. 14 is a development view of a conductive holder according to a ninth embodiment.

FIG. 15 is a sectional view of a conventional high-voltage transformer.

[Explanation of symbols]

 7 Discharge Lamp 17, 87 High Voltage Transformer 17a Secondary Winding 18 Spool 19 Core 20, 80 Case 21, 84 Substrate 22, 82 Conductive Holder 83 High Voltage Cord 85, 86 Other Electrical Parts 100 Circuit Container

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01F 30/00 H05B 41/02 Z 41/29 Z

Claims (12)

[Claims] 1. A high-voltage transformer including a core, a secondary winding, and a primary winding, comprising: an insulating material that covers and integrates the core and the secondary winding; and the secondary as the primary winding. A high-voltage transformer, comprising: a conductive holder, which is arranged so as to surround the winding and has fixing portions to the base at both ends. 2. The high voltage transformer according to claim 1, wherein the conductive holder is integrally molded in the insulating material. 3. The insulating material comprises a case made of resin and a filling resin filled in the case, the core and the secondary winding are housed in the case, and the filling resin is filled. The high voltage transformer according to claim 1 or 2, wherein the high voltage transformer is integrated in the case. 4. The high voltage transformer according to claim 3, wherein the case is provided with a connecting portion with the base. 5. The high voltage transformer according to claim 1, wherein the conductive holder covers at least a high voltage end of the secondary winding. 6. The conductive holder has a main conducting portion through which a current as the primary winding flows, and a cover portion extending from the main conducting portion and covering the high voltage end. The high-voltage transformer according to item 5. 7. The high voltage transformer according to claim 1, further comprising a high voltage cord, wherein a high voltage end of the secondary winding is connected to the high voltage cord. 8. A discharge lamp circuit in which a high-voltage transformer including a core, a secondary winding, and a primary winding is mounted on a substrate on which other electric components are mounted, wherein the high-voltage transformer includes the core and the secondary winding. An insulating material that covers and integrates the secondary winding; and a conductive holder that is disposed so as to surround the secondary winding as the primary winding and that has a fixing portion to the substrate provided at both ends. A discharge lamp circuit, wherein a conductive pattern of a substrate and both ends of the conductive holder are electrically connected to each other. 9. The discharge lamp circuit according to claim 8, wherein at least a low-voltage end of the secondary winding is connected to a conductive pattern of the substrate. 10. The discharge lamp circuit is housed in a circuit container, and the conductive holder is a cover portion extending between other electric components in the circuit container and a high voltage end of the secondary winding. The discharge lamp circuit according to claim 8 or 9, further comprising: 11. The conductive holder has a main conducting portion through which a current as the primary winding flows, and the cover portion is formed to extend from the main conducting portion. 10. The discharge lamp circuit according to 10. 12. The high-voltage cord, which is separate from the conductive pattern of the substrate, and the high-voltage end of the secondary winding is connected to the high-voltage cord. The discharge lamp circuit according to any one.